1. Field of the Invention
The present invention relates to an electric motor incorporated in a compressor or the like mounted on an air conditioner or the like, and more particularly, it relates to an attachment structure of a lead wire drawn out of a stator winding.
2. Background Art
As shown in FIG. 11, an electric motor 1a incorporated in a compressor 1 mounted on an air conditioner or the like is constituted of a rotor 3 fixed to a rotation shaft 2, and a stator 4 disposed on an outer peripheral side of the rotor 3 via a small gap.
A top plan view of the stator 4 is shown in FIG. 12. The stator 4 is constituted of a stator core 5 having a plurality of (six in the drawing) magnetic pole teeth disposed in a peripheral direction at a predetermined interval so as to project toward a central portion (the rotor), and stator windings 7a to 7f wound around the respective magnetic pole teeth of the stator core 5 via insulating members 6. In an end surface portion of the stator core 5, a plurality of winding terminal receiving portions 8a to 8f are disposed integrally with the insulating members 6. These winding terminal receiving portions 8a to 8f are dispersedly disposed on the end surface portion of the stator core 5 in the peripheral direction to accept winding ends of the respective stator windings 7a to 7f closely disposed.
The stator windings 7a to 7f are connected to a power source via a lead wire unit 11. The lead wire unit 11 is constituted of lead wires 13a to 13f, winding side connection fittings 12 (FIG. 13) electrically connected to respective one ends of the wires and attached to the winding terminal receiving portions 8a to 8f, and a power source connector 14 disposed on the other end of the lead wire.
In general, attaching of terminal portions of the respective stator windings to the winding terminal receiving portions 8a to 8f and inserting/fixing of the connection portion 12 can be automated. In the attaching of the lead wire unit 11, however, for example, with a three-phase motor, two for each phase, that is, six winding terminals 9a to 9f in total are present, and six connection fittings 12 and six lead wires 13a to 13f are therefore necessary. Therefore, manufacturing cost of the lead wire unit 11 is raised, further a large number of processes are necessary for attaching the unit, and from this aspect, cost also increases.
Moreover, for the conventional connection fitting 12, while the lead wires 13a to 13f are inserted into lower cutouts of the connection fittings 12 in a radial direction, the connection fitting 12 is pressed downward to break insulation of the lead wire and electrically connect the connection fitting 12 to the lead wire. In this case, the lead wires 13a to 13f turned in the radial directions to be inserted into the connection fittings 12 are led around in the peripheral direction and connected to the power source connector 14, and therefore flexing forces act on the lead wires 13a to 13f in the connection fittings 12. Therefore, when an external force is further applied to the lead wires 13a to 13f and the connection fittings 12, there is a possibility that disconnection and connection defect occur with the lead wire.
In order to avoid the aforementioned disadvantage, as shown in FIG. 14, the flexing force is prevented from acting on the lead wire. Winding terminal receiving portions 16 for a three-phase motor are collectively disposed in one place on the end surface of the stator core 5, the winding terminal is attached in a vertical direction to a connection terminal 15 disposed in the winding terminal receiving portion 16, and further a bifurcated terminal conductor 18a disposed on a terminal plate 17 is pressed from above and inserted into the connection terminal 15 to put the winding terminal between leg portions, so that the winding terminal is electrically connected to the terminal conductor 18a. The other end of the terminal conductor 18a whose one end is vertically inserted into the connection terminal 15 is bent as a terminal conductor 18b at right angles in the terminal plate 17 and extended to the outside in the radial direction. A casing 19 is formed to surround the terminal conductor 18b. The terminal conductor 18b and casing 19 are joined to a winding end side connection portion 11a of the lead wire unit 11 to constitute a connection terminal for electric connection.
A connection structure of FIG. 14 can solve a problem of flexing force exerted on the lead wire in FIGS. 12 and 13, but it is necessary to lead a far detached winding terminal along the insulating member 6 to the winding terminal receiving portion 16. Therefore, a winder structure for performing this operation becomes complicated. Furthermore, in this case, the terminal plate 17 needs to be integrally molded with a terminal 18 by a resin mold, and this is one factor to cause cost increase.
The present invention has been developed in consideration of the aforementioned circumstances, and an object thereof is to provide a highly reliable motor in which to attach a lead wire unit to the motor, the number of operation processes can be reduced to achieve cost decrease, and further a damage associated with leading of a lead wire does not easily occur.
To achieve the aforementioned object, according to one embodiment of the present invention, there is provided a motor comprising a plurality of windings wound around a stator core; a plurality of winding terminal receiving portions, disposed on an end surface portion of the stator core at an interval in a peripheral direction, for individually receiving a plurality of winding terminal portions; a plurality of first conductive connection fittings, attached to said respective winding terminal receiving portions, for fixing said winding terminal portions to said winding terminal receiving portions and for electrically connecting with said winding terminal portions; a plurality of second conductive connection fittings whose one surface side is provided with a projection for contacting said first connection fitting and whose other surface side is provided with a lead wire which is electrically connected to said winding terminal portion and which extends through the second conductive connection fittings in the peripheral direction of said stator core; and a terminal plate having connection fitting receiving portions to which said plurality of second connection fittings are attached and which are dispersed in the peripheral direction so as to correspond to said plurality of winding terminal receiving portions.
According to another embodiment, there is provided a motor comprising a plurality of windings wound around a stator core; a plurality of winding terminal receiving portions, disposed on an end surface portion of said stator core at an interval in a peripheral direction, for individually receiving a plurality of winding terminal portions; a plurality of connection fittings which fixes said winding terminal portion to said winding terminal receiving portion and which electrically connects with said winding terminal portion on one side, said plurality of connection fittings having a groove through which a lead wire connected to said winding terminal portion passes in the peripheral direction of said stator core on the other side; and a terminal plate having connection fitting receiving portions to which said plurality of connection fittings are attached and which are dispersed in the peripheral direction so as to correspond to said plurality of winding terminal receiving portions; said connection fitting being beforehand attached to either of said winding terminal receiving portion and said terminal plate. According to this embodiment, since the number of materials or the number of components can be reduced, the number of processes and cost can further be reduced.
The winding terminal portion may be drawn in a radial direction of a stator and fixed to the first connection fitting. This can prevent a flexing force from acting on the lead wire in a lead wire connection portion.
The connection fitting may be attached to constitute a pressure contact type terminal for breaking an insulation coat of the winding or the lead wire disposed beforehand for electrically conductive contact. This can simplify an assembly operation.
The terminal plate is provided with a guide groove for guiding the lead wire, and this guide groove may have a width substantially equivalent to a diameter of the lead wire, and also have a depth such that a plurality of lead wires can be superposed and accommodated. This can prevent the lead wires from jumping out or crossing one another when the wires are led around.